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11.
为了保障锂离子电池的使用安全,提出了基于带渐消因子的扩展卡尔曼滤波(Fading Extended Kalman Filter,FEKF)的电池状态在线监测方法. 建立锂电池一阶等效电路模型,利用递推最小二乘法进行锂电池状态参数在线辨识,建立状态方程;引入最优渐消因子,构造FEKF,得到端电压残差;使用端电压残差序列构造χ2分布的诊断函数,计算误检率与状态参数异常阈值. 实验结果显示利用FEKF生成的残差能更早对异常状态进行告警,证明FEKF能够显著提高χ2检验对锂电池内部缓变型异常状态判断的准确率.  相似文献   
12.
必要的敬畏     
正在敬畏中,我们坚守自然的奇异性,向未知敞开心扉。无怪乎它是科学想象力的核心所在。当科学范式被打破时,科学家不得不进入未知领域。这就是科学革命来临之际,托马斯·库恩(Thomas Kuhn)所认定的。科学家的世界图景变得站不住脚,学科中公认的真理遭到彻底的怀疑。  相似文献   
13.
针对在风速、同步发电机负载变化情况下,液压蓄能式风力机组并网转速控制问题,提出一种新型并网转速控制方法——解耦广义预测优化控制方法(Decoupled Generalized Predictive Optimization Control, DGPOC).首先,DGPOC利用基于广义预测的前馈解耦方法解除变量马达摆角和蓄能器比例阀开度之间的耦合关系,进而调节蓄能器比例阀,依靠蓄能器吸收波动流量,同步调节变量马达摆角实现恒转速控制,解决因风速、同步发电机负载变化引起的变量马达转速波动问题; 其次,将蓄能器比例阀的能量损耗作为性能约束项,加入到优化目标函数中,求取最优控制量,从而提高液压蓄能式风力机组风能利用率; 最后,利用建立的MATLAB-AMESim联合仿真实验平台验证DGPOC方法的有效性.实验结果表明: DGPOC方法不仅可以实现变量马达摆角和蓄能器比例阀开度两个变量的解耦,提升变量马达转速控制的快速性及鲁棒性,而且能够降低系统的能量损耗.  相似文献   
14.
A noteworthy feature of the living world is its bewildering variability. A key issue in several biological disciplines is the achievement of an understanding of the hereditary basis of this variability. Two opposing, but not necessarily irreconcilable conceptions attempt to explain the underlying mechanism. The gene function paradigm postulates that phenotypic variance is generated by the polymorphism in the coding sequences of genes. However, comparisons of a great number of homologous gene and protein sequences have revealed that they predominantly remained functionally conserved even across distantly related phylogenic taxa. Alternatively, the gene regulation paradigm assumes that differences in the cis-regulatory region of genes do account for phenotype variation within species. An extension of this latter concept is that phenotypic variability is generated by the polymorphism in the overall gene expression profiles of gene networks. In other words, the activity of a particular gene is a system property determined both by the cis-regulatory sequences of the given genes and by the other genes of a gene network, whose expressions vary among individuals, too. Novel proponents of gene function paradigm claim that functional genetic variance within the coding sequences of regulatory genes is critical for the generation of morphological polymorphism. Note, however, that these developmental genes play direct regulatory roles in the control of gene expression.  相似文献   
15.
为了加固梁柱节点、避免框架结构出现"弱节点"的破坏模式、提高框架结构整体的抗震和耗能能力,研制出一种具有自主知识产权的位移放大型扭转阻尼器(DATD),并对其进行数值分析和试验研究.首先,设计了18个具有不同参数的DATD,建立其有限元模型进行数值分析;随后,设计并制作了一个DATD,进行性能试验并与有限元分析结果对比.结果表明:DATD滞回曲线饱满,耗能能力强;有限元分析与性能试验的滞回曲线吻合较好,且随着加载位移的增加,两者间误差变小,因此可以采用建立的有限元模型来研究DATD的力学性能.最后,对DATD进行参数影响分析,研究了铅芯直径、铅芯距中轴距离、橡胶层直径、橡胶层厚度及橡胶剪切模量对其特征参数的影响,结果表明:DATD的屈服剪力、等效刚度、等效阻尼比及耗能系数随着铅芯直径增大而明显增大,随着铅芯距中轴距离的增大略有增大;随着橡胶层直径、橡胶剪切模量的增大,屈服剪力及等效刚度逐渐增大而耗能系数及等效阻尼比逐渐减小;4个特征参数均随着橡胶层厚度的增大而略微减小.  相似文献   
16.
In contrast to differential equations, P systems are an unconventional model of computation which takes into consideration the discrete character of the quantity of components and the inherent randomness that exists in biological phenomena. The key feature of P systems is their compartmentalised structure which represents the heterogeneity of the structural organisation of the cells, and where one can take into account the role played by membranes in the functioning of the system, for example signalling at the cell surface, selective uptake of substances from the media, diffusion across different compartments, etc. We show here that P systems can be a reliable tool for Systems Biology and could even outperform in some cases the current simulation techniques based on differential equations. We will also use a strategy based on the well known Gillespie algorithm but running on more than one compartment called Multi-compartmental Gillespie Algorithm.  相似文献   
17.
The Liu Wei Di Huang Wan is a formula of a traditional Chinese medicine that is used to treat asthma patients and has been shown to have several important properties,such as antioxidant and free radical scavenging activities.The influence of an extract of Liu Wei Di Huang Wan on the labeling of blood constituents with technetium-99m was investigated.Anticoagulated blood(Wistar rats) was incubated with the extract,stannous chloride and technetium-99m,as sodium pertechnetate.Samples were centrifuged and aliquots of plasma and blood cells were separated and precipitated with trichloroacetic acid,to obtain soluble and insoluble fractions of the blood constituents.The percentage of radioactivity(%ATI) in all the fractions was determined.The analysis of the results shows that the extract at the highest concentration used(70 mg/mL) decreased significantly(P<0.05) the %ATI(from 96.48 ± 1.19 to 54.46 ± 7.38) on blood cells compartment,(from 81.11 ± 4.15 to 61.33 ± 4.74) on insoluble fractions of blood cells and(from 65.91 ± 2.44 to 13.15 ± 3.62) on insoluble fractions of plasma.In conclusion,the results suggest that the substances present on this extract can alter this labeling process,probably due to(i) redox properties(antioxidant and chelator activities) and/or(ii) specific actions in the binding sites where the 99mTc would be bound on the blood constituents.As a consequence,precaution is suggested on the interpretation of the nuclear medicine results from performed with blood constituents labeled with 99m Tc in patients that have undertaken LWDHW,although the current findings were obtained in experimental animal models.  相似文献   
18.
小绿人     
"艾弗森先生,你需要来一趟你儿子的学校." "我正在准备一宗案子.这事就不能等到周五吗?"艾弗森先生面前的屏幕中的女人撅起嘴唇.她是沃瑟姆老师,也是负责艾文的首席教师,"这事十分紧要,我们需要商议一下." "好吧,咱们现在就谈." 沃瑟姆老师的额头上顿时形成几条代表受挫的皱纹,转眼又消失不见.她将头发拂到一侧耳朵后面.  相似文献   
19.
为在路径规划过程中得到一条适用于实际情况的最优路径,并克服遗传算法自身固有的易收敛于局部最优解和复杂度较高的缺点,提出一种基于Q-IGA(Q-standard Improved Genetic Algorithm)算法动态搜索贝塞尔曲线控制点的路径规划算法. 该算法摒弃利用贝塞尔曲线直接拟合最优路径的静态方式,使路径搜索与控制点搜索两个过程同时进行;并且在选择算子中添加一个判断准则,利用Q值检验法剔除相似度较高的解决方案,增强种群的多样性;与此同时,优化适应度函数,加入机器人体积及转弯角度带来的代价,使选择出的路径是一条距离较短且与障碍物保持安全距离的合理路径. 仿真结果表明,Q-IGA算法比改进人工势场法和混合遗传算法得到的路径更为合理,可降低机器人耗能,减少搜索时间,更适于实际的工业应用.  相似文献   
20.
以燃气轮机透平端RSS(旋转对称支承板)机座为研究背景,通过用D’Alembert原理建立了RSS机座的拓补优化域和等价边界条件,从而实现了用均匀化方法的RSS机座拓扑结构优化,得到了旋转对称的弧形支承板拓扑结构的机座.然后,结合原来RSS机座的机构特征在ANSYS workbench中建立了RSS拓补结构光滑有限元模型,并进行了工作条件下的模态分析,以前三阶模态振型中轴承座的振型作为当量静载荷加载到原模型对比计算,验证边界条件的正确性.以RSS机座弧形支承板的四个关键尺寸为设计变量,以机座的变形量和应力为目标函数,进行了随频率变化的动态优化设计.通过优化改变了RSS拓补结构的动态特性,使固有频率远离了工作频率.  相似文献   
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